1920 or prior Villa

Villa
Durable materials used
Mainly use native timber which is naturally durable regardless of moisture presence.
1930 Bungalow

More simplified envelope
Mainly use native timber which is naturaly durable.
Starting to use exotic timber which is less durable than native
More roof to wall junctions showing which are volnarable to water ingress.
1940-50 State house

Further simplified envelope almost without any high weathertightness features.
Use combination of native and exotic timber as structure materials.
Universal shape to meet high volume and low price post WW2 housing demand
1960 Character bungalow

Relatively more variaties of different envelopes availabe comparing with state houses.
Pine started to use as main structure timber. Mainly CCA treated and wet delivered.
Simple house shape with very few weathertightness high risk features.
1970 kitset

Even more simplified envelope with no high risk weathertightness features.
Aluminium joinery started to emerge.
1980 hardie Plank revolution

Hardie plank combined with aluminium joinery were dominating
Variety of different cladding materials
More complicated houses started to build
First leaky house with treated timber started
1990 Plaster is good

Computerised Automated Design (CAD) + Monolithic cladding + Untreated timber + Low skilled labour + Height relation to boundary = Leaky house